FDA issues complete response letter for Tysabri supplemental filing in SC form for multiple sclerosis – Biogen

Biogen Inc. announced that it has received a Complete Response Letter from the FDA for its supplemental Biologic License Application (sBLA) for a new subcutaneous route of administration of Tysabri (natalizumab) to treat relapsing multiple sclerosis (MS). The CRL indicates that the FDA is unable to approve the Company’s filing as submitted. Biogen is evaluating the CRL and will determine next steps in the U.S.

In early April 2021 the European Commission granted marketing authorization for a subcutaneous injection of Tysabri (natalizumab) to treat relapsing-remitting multiple sclerosis. The SC and IV formulations of Tysabri are dosed 300 mg, every four weeks (Q4W) by a healthcare provider. The SC option expands the clinical settings, beyond infusion centers, where patients can be treated. In addition, the SC formulation is administered in a shorter timeframe compared to the IV formulation and allows physicians to reduce or remove the post-dose observation period for some patients after six doses as clinically appropriate.